At least here the player widget continued playing in the background
when closing the window with ESC, it seems it's actually only hidden.

Signed-off-by: François Revol <revol@free.fr>

Remove useless trailing \
Remove trailing spaces
Add missing empty lines

autopep8 -ir -j2 --select=E301,E302,E502,W291,W293,W391 .

Diff quickly checked.

autopep8 -ir -j2 --select=E303,E125
Diff checked manually.

This is recommended by Debian.
closes #618

closes #823